4IUG:
reference: The crystal structure of acidic beta-galactosidase from Aspergillus oryzae., Maksimainen MM, Lampio A, Mertanen M, Turunen O, Rouvinen J, Int J Biol Macromol. 2013 Sep;60:109-15. doi: 10.1016/j.ijbiomac.2013.05.003., Epub 2013 May 17. PMID: 23688418

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).